John Kerry actually said...

The word of the United States must mean something. It is vital currency in foreign relations and international and allied commitments.

I think that it is fair to say that our interests would be seriously set back in many respects if we are viewed as not capable--or willing, ...

the President's actions will make us more secure, less likely that Assad can use his weapons or chooses to use his weapons.

Well, if we fail to act, we are going to have fewer allies.